Problem

When a query knob is read while query settings are still pending resolution, the dassert(_isKnobReadAllowed(knob.id)) in QueryKnobConfiguration::get() aborts with only the raw expression:

Invariant failure: \_isKnobReadAllowed\(knob.id\)
  at src/mongo/db/query/query\_knobs/query\_knob\_configuration.h

The message does not identify which knob was read, forcing manual correlation to figure out the offending PQS-settable knob.

Change

Attach a diagnostic message to the assertion naming the knob's wire name, e.g.:

PQS\-settable query knob 'internalQueryMaxBlockingSortMemoryUsageBytes' read while query settings are pending resolution

The message is built by a helper referenced only from the debug-only dassert (guarded by if constexpr (kDebugBuild)), so it is compiled out of release builds and has no production cost.